noun - Katabatic Wind is a downslope wind that carries high density air from a higher elevation down a slope under the force of gravity that can rush down elevated slopes at hurricane speeds, but most are not that intense and many are on the order of 10 knots or less (e.g., Mistral in the Mediterranean, Bora (or Bura or бура) in Serbo-Croatian and the Adriatic Sea, Santa Ana Winds in southern California, Oroshi in Japan, The Barber in New Zealand, бора in Bulgarian and Russian, μπόρα in Greek, burja in Slovene, buòra in Italian, Polish and Turkish: Venetian) is a northern to north-eastern wind in the Adriatic Sea, Croatia, Montenegro, Italy, Bulgaria, Greece, Slovenia, Poland, Russia (Novorossiysk) and Turkey.
In Greek, the word "bora" (μπόρα) describes an intense summer rain that lasts for a few minutes. In Croatian "burno" means "violently" and is commonly used to describe the weather.
The changeable bora can often be felt all over Montenegrin Littoral, Dalmatia, Istria, the Slovenian Littoral, Trieste, and the rest of the Adriatic east coast. It blows in gusts. The Bora is most common during the winter. It blows hardest, as the meteorologist Baron Ferdinand von Wrangel explained it by extending Julius Hann's explanation of Alpine katabatic winds to the north Adriatic, when a polar high-pressure area sits over the snow-covered mountains of the interior plateau behind the Dinaric coastal mountain range and a calm low-pressure area lies further south over the warmer Adriatic. As the air grows even colder and thus denser at night, the Bora increases. Its initial temperature is so low that even with the warming occasioned by its descent it reaches the lowlands as a cold wind. The wind takes two different traditional names depending on associated meteorological conditions: the "light bora" (Italian: Bora chiara) is Bora in the presence of clear skies, whereas clouds gathering on the hilltops and moving towards the seaside with rain or snow characterize the "dark bora" (Bora scura).
from Greek katabatikos meaning going downhill
drainage wind, fall winds, Williwaw.